Conventional locking devices installed in offices or apartments have low security because keys or pass-cards used to unlock the locking devices are easily lost and copied. Furthermore, users must carry the keys or pass-cards and memorize pass numbers. To solve the problems of the conventional locking devices, a variety of studies on personal identification techniques with high security and convenience have been carried out.
Biometric systems are commercially used in order to solve the problems of the conventional locking devices. The biometric systems extract biometric information (fingerprint, face, iris, cornea, hand shape, vein of the back of the hand, voice and so on) of a person and compare the extracted biometric information with biometric information stored in a memory to identify the person. The biometric systems take a picture of a specific part of the body of the person using a camera to extract biometric information for recognition. A personal identification system using iris recognition is widely used.
A dedicated camera system is used to recognize the iris of a user. Conventional dedicated camera systems are divided into two. The first one performs a position adjustment function using a face recognition stereo camera and recognizes the correct position of an iris to take a picture of a focused iris, which is disclosed in Korean Patent Application No. 10-200300002822 entitled “Iris recognition system and iris recognition method using stereo face recognition”. However, this camera system is irrelevant to iris recognition using a mobile device. The second camera system takes a picture of a focused iris using a camera having an auto zooming and auto focusing functions, which is used by LG, Panasonic and OKI. However, this camera system requires a large-size camera and thus the manufacturing cost is increased. Accordingly, it is difficult to apply the camera system to a mobile device.